Patent No. U.S. 7,232,479 B2
Dacral of Creil, France has obtained a patent for a coating composition for a metal substrate having a free outer surface, formed by a layer of zinc or of a zinc-based alloy, wherein the coating composition is comprised (in percent by weight): sodium and/or potassium and/or lithium silicate(s) incorporated in the form of an aqueous solution: 3-35%; surfactant: 0.01-1%; a silane, in an amount of up to 50% by weight of dry coating; water: qs 100% and wherein the composition has a surface tension value of between 20 mN/m and 50 mN/n.